1986 4runner 22re hot start isuues with AFM?
#1
1986 4runner 22re hot start isuues with AFM?
I have a 1986 4runner with the 2.4L 22re. the body has 219,000k and the engine is rebuilt with around 40,000k.
The problem is that when the vehicle is up to operating temperature if it is shut off it will go into a no start condition. Sometimes using a generous amount of starter fluid tends to get it started, or oddly enough unplugging the air flow meter allows it to start for about 4-5 seconds, (giving me enough time to plug it back in to keep it idling).
After i figured out unplugging the AFM allowed it to start i figured that was the cause of my problems. I followed the testing procedures and found out that the resistance between the pins were all in spec. I've tried adjusting the air flow meter thinking that would help, and it has with the idle of the engine but no change when trying to start when the vehicle is up to temp.
I am at a loss, I've checked all the vacuum lines with starter fluid, even though there are two lines coming from the intake manifold that the original owner just plugged up with screws and i'm not able to find out where they go. there was a ground wire for a vacuum line solenoid that connects to the egr system that i connected and after that it seemed to start up at warmer temperatures, but after reaching full operating temperatures it still wont start.
I'm just not sure if its the AFM still or not. with the afm cover off i can move the needle off of the switch and hear the fuel pump relay activate, and what sounds like a little pump activate as well. While holding the AFM and having someone in the car crank it, it will start up with a little throttle. It just doesnt make sense to me that the car will start while the AFM is unplugged and that fuel pump relay not activating. If anyone has any advice or anymore knowledge on if its the AFM or another issue id appreciate the help.
The problem is that when the vehicle is up to operating temperature if it is shut off it will go into a no start condition. Sometimes using a generous amount of starter fluid tends to get it started, or oddly enough unplugging the air flow meter allows it to start for about 4-5 seconds, (giving me enough time to plug it back in to keep it idling).
After i figured out unplugging the AFM allowed it to start i figured that was the cause of my problems. I followed the testing procedures and found out that the resistance between the pins were all in spec. I've tried adjusting the air flow meter thinking that would help, and it has with the idle of the engine but no change when trying to start when the vehicle is up to temp.
I am at a loss, I've checked all the vacuum lines with starter fluid, even though there are two lines coming from the intake manifold that the original owner just plugged up with screws and i'm not able to find out where they go. there was a ground wire for a vacuum line solenoid that connects to the egr system that i connected and after that it seemed to start up at warmer temperatures, but after reaching full operating temperatures it still wont start.
I'm just not sure if its the AFM still or not. with the afm cover off i can move the needle off of the switch and hear the fuel pump relay activate, and what sounds like a little pump activate as well. While holding the AFM and having someone in the car crank it, it will start up with a little throttle. It just doesnt make sense to me that the car will start while the AFM is unplugged and that fuel pump relay not activating. If anyone has any advice or anymore knowledge on if its the AFM or another issue id appreciate the help.
#2
You smelling gas after it cranks back up?
Test the ECU temp sending unit.
Also, test the cold start injector thermo time switch. This switch went bad on my 92, and hot starts were a big PITA.
Test the ECU temp sending unit.
Also, test the cold start injector thermo time switch. This switch went bad on my 92, and hot starts were a big PITA.
#3
yes there is a smell of gas while the vehicle is running.
I will have to look up the procedures on the temp sending unit.
the cold start injector works fine, but from my understanding it shouldnt be operating once the vehicle is up to operating temperature, correct?
I will have to look up the procedures on the temp sending unit.
the cold start injector works fine, but from my understanding it shouldnt be operating once the vehicle is up to operating temperature, correct?
#5
Is the ECU temp sending unit located on the thermostat housing to the right of the intake manifold? if so i found out that there aren't any wires connecting to it. I found a loose green wire hanging around and i just grounded it to the body, i was wondering if that may have been for the temp sending unit? This could be he cause of my problems considering the ecu wont even be getting the signal.
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#8
#11
i plugged in the loose green/black wire to the ECU temp sending unit and it didnt seem to make too much of a difference. What still doesnt make sense to me is that when the AFM is unplugged, the car starts right up?
#12
Registered User
#13
Registered User
iTrader: (-1)
The thermo switch on top of the thermostat housing is for the fuel pressure up system.
The hot start issue has a TSB, it requires a thermo switch with a different range.
There is at least one detailed thread here with the tests you want to run. In short make sure your switch works
The hot start issue has a TSB, it requires a thermo switch with a different range.
There is at least one detailed thread here with the tests you want to run. In short make sure your switch works
#14
The thermo switch on top of the thermostat housing is for the fuel pressure up system.
The hot start issue has a TSB, it requires a thermo switch with a different range.
There is at least one detailed thread here with the tests you want to run. In short make sure your switch works
The hot start issue has a TSB, it requires a thermo switch with a different range.
There is at least one detailed thread here with the tests you want to run. In short make sure your switch works
#15
Registered User
This might help, shows how AFM is tied to VSV, sensors & ECU for an '87:
Last edited by Paul22RE; 02-11-2019 at 11:29 AM.
#16
Registered User
Here is the rest of the AFM circuit:
#17
Registered User
iTrader: (-1)
i put a spade clip on and connected to the thermo switch on top of the thermostat housing, but im not sure if that is the correct wire or not (didnt make any difference). when the wire is connected to a ground you can hear the switch on the egr vaccum line on the rear of the valve cover. ill post pictures the next time i have a chance.
I'm pretty sure this green black wire is the TSW signal, but don't take my word for it. Put your voltmeter on it and probe the location out at the ECU connector.
#18
checked the wire continuity to the ecu on the green/black wire. i was getting continuity to more than 8 pins on the ecu. ill need to go through the wiring harness to see where its shorting out to the other wire. other than that i did notice rust on the ecu, meaning its been in some contact with water, does anyone know the ecu testing procedures?
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09-19-2011 12:30 AM